1. Field of the Invention
This invention relates to an apparatus for pelletizing or agglomerating finely divided particulate or pulverant materials into spheroidal pellets of an advantageous pellet size distribution in preparation for subsequent treatment in which it is advantageous and desirable to have the material in the form of pellets or balls.
2. Description of the Prior Art
Apparatus disclosed by the prior art for pelletizing finely divided particulate materials include rotating discs or drums, sometimes referred to in general as balling devices. As an example of such prior art devices, an inclined balling drum is described in U.S. Pat. No. 2,707,304 as suitable for the formation of balls, pellets, or glomerules from moisture-containing pulverant material. To similar effect is an apparatus described in U.S. Pat. No. 3,060,496 as a frusto-conical drum of relatively small depth (read pan) useful to pelletize moisture-containing pulverant material. In U.S. Pat. No. 2,876,491, an inclined pelletizing disc is described. The apparatus consists of a rotary inclined disc having a collar extending outward from the damming edge which is inclined to the plane of the disc at an angle of 5.degree. to 20.degree., preferably 10.degree. to 15.degree..
For a general review of balling devices, see The Encyclopedia of Chemical Process Equipment, Mead, Ed., Reinhold Publishing Corp., New York, 1964, pp. 48-50.
Although the prior art devices are generally successful in providing pellets of suitable size distribution from finely divided particulate materials, they nonetheless suffer from various disadvantages and difficulties. Principal among these disadvantages and difficulties are apparatus complexity, a less than rapid rate of pelletization for large quantities of material, and high cost of equipment. Thus, the discovery of an apparatus suitable for pelletizing finely divided particulate materials into spheroidal pellets of an advantageous pellet size distribution, which apparatus (1) has no motors or moving parts and (2) is simple to construct from readily available and relatively inexpensive materials is believed to be a decided advance in the state of the art.